"And yet, at other times, on other matters, I have been told that I'm the custodian of the nuclear Non-Proliferation Treaty - sometimes by the very people who tell me to mind my own business when it comes to Iran," he said.

"I don't put much stock in either designation. I'm neither a custodian nor a technician. I'm merely someone who is trying to do his job."

ElBaradei steps down at the end of November, handing over to Yukiya Amano, a veteran Japanese diplomat.